From the Rio Grande to the Mediterranean Sea

Using labor-force supply and demand, UC San Diego researchers predict Mexico migration surge to U.S. is over

Gordon Hanson, acting dean of the UC San Diego School of Global Policy and Strategy. Photos by Erik Jepsen/UC San Diego Publications

New research from the University of California San Diego finds the great migration surge of Mexico-born workers crossing into the United States is over—and will remain this way for years to come. Instead, the new migration hot spot will be workers moving from Northern Africa into Europe.

The research by Gordon Hanson and Craig McIntosh of the School of Global Policy and Strategy has ramifications for policy changes in Washington, as well as key regions in other parts of the world.

“The era in which immigration levels are rising in a way that can feel out-of-control appears to be coming to an end in the United States, while it seems to be just beginning in the European Union,” they write in “Is the Mediterranean the new Rio Grande? US and EU Immigration Pressures in the Long Run.”

The paper appears in the Fall 2016 issue of the Journal of Economic Perspectives. Hanson is the Pacific Economic Cooperation Professor in International Economic Relations, director of the Center on Global Transformation and acting dean of the School of Global Policy and Strategy. McIntosh is a professor of economics, and heads the Policy Design and Evaluation Lab.

Craig McIntosh, School of Global Policy and Strategy professor and co-director of the Policy Design and Evaluation Lab.

The paper differs from previous migration research in that it links birth rates to labor supply and demand in order to predict potential migration patterns. In the 1960s, high birth rates for baby boomers in the U.S. ended, causing a sharp decline in working-age individuals 20 years later. During the same period of time in Mexico, the birth rate was more than double what it was in the U.S., which resulted in a far greater number of young Mexican workers in the late 1980s.

“One thing we’re happy to reiterate with this research is that one of the most fundamental concepts regarding the economics of immigration is that, internationally, labor flows are mostly driven by differences in income between countries,” said Hanson, an expert on immigration and labor whose research on U.S.-China trade helped shape the current discussion on global trade. “But we also wanted to address another aspect of economic migration, focused on labor supply and demand. The results led to better predict where migration would likely happen in the future.”

The study included individuals between ages 15 and 64 in the Database on Immigrants in OECD Countries (DIOC). Analyzing this data, the researchers show that the 32.8 million working-age immigrants who lived in the U.S. in 2010 represented 41.6 percent of all foreign-born individuals living in an OECD country. Mexico accounted for just under one third of U.S. working-age immigrants, and the authors recognize the Mexico-to-U.S. migrant flow as one of the largest international migration episodes that the world has ever seen.

“The argument here suggests that when international borders also draw a line between nations with significant differences in population growth, pressures for migration will result,” they write. “Bilateral migration flows will tend to be high between countries that are neighbors and that occupy different ends of [the] population growth continuum.”

However, a different location for mass migration emerges once they examined projected, or future, birth rates. Using the United Nations World Population Prospects database, which projects population growth over time, the authors looked at population growth between 2040 and 2050. Whereas growth in the 1970s in Mexico and other Latin American countries was over 10 percent, the only regions with population growth projected to be similarly high in the next 30 years is in most of sub-Saharan Africa.

They then project how migration pressures shift location as population growth centers shift. Mexico no longer has high birth rates, with numbers that are now comparable to the U.S. It is in parts of Africa where populations are expected to rise, and their neighbor to the north—specifically countries in the European Union—will receive the most pressure from migration.

“Whereas in the 1970s, the world was neatly divided between a high-income and low-population-growth North and a low-income and high-population-growth South, by the 2040s the only high-population-growth countries likely to remain will be in sub-Saharan Africa and parts of the Middle East,” they write. “These new triggers are being tripped in a demographic environment that is ideal for perpetuating emigration well into the future.”

Their work estimates a nearly triple effect of first-generation immigrants to the United Kingdom, Spain and Italy. Additionally, African-born first-generation migrants in their study who work and live outside of sub-Saharan Africa will grow from 4.6 million to 13.4 million through 2050.

Hanson and McIntosh outline implications for their migration research in the U.S. and abroad. They say changes could be addressed in U.S. government spending on immigration enforcement, which has reached tens of billions of dollars annually. While the EU does allow for free movement of workers among labor states, immigration enforcement from neighboring countries — including those in Northern Africa and the Middle East — could benefit from greater coordination of immigration policy, they say.

“Labor supply cannot predict migration patterns with 100 percent accuracy, but it does create a platform for understanding where the conditions for future migration are ripe,” McIntosh said. “We hope that understanding this picture will help policymakers respond to the actual pressures for future migration rather than reacting to factors that were set in place 20 years prior.”